Zoology and wildlife conservation

A sex difference in the human brain and its relation to transsexuality

Article Abstract:

The level of central subdivision of the bed nucleus of the stria terminalis (BSTc) is larger in homosexual men than in heterosexual women but male-to-female transsexuals have a female-sized BSTc regardless of their sexual orientation. Interactions between early brain growth and sex hormones are most likely responsible for alterations in gender identity while BSTc size is independent of sexual orientation and uninfluenced by sex hormones produced in adulthood. The hypothalamus of six male-to-female transsexuals is analyzed. The BSTc size of women and transsexuals is comparable and sex hormone level in adulthood have no influence on BSTc volume.

La difference vive

Article Abstract:

Magnetic resonance imaging studies of language representation in the brains of men and women reveal that while phonological tasks are lateralized in the brains of men with only the left inferior frontal gyri being active, in women these tasks activate responses in both the right and left side of the inferior frontal gyri. These experiments do not distinguish between essential activities and correlated activities of the brain, making the results inconclusive.

Seeing the tree for the woods

Article Abstract:

William James suggested that the ability to observe some things while ignoring others was a result of the mind selecting certain data and suppressing other. Several experiments have been conducted to confirm James' theory. Chelazzi and his group of psychologists trained monkeys and proved James' theory by showing that the cells in the brain get activated when a perceived object is recognized.